By default the server will look for an html file at the /login route. So you should configure it for html5 navigation to return you index.html for any route it receives.

EDIT:

To do so in webpack, as you suggest in the comments, you can add this to your webpack dev server config:

historyApiFallback: true

index.html should be the default, so no need to specify it.

Also please note that urls containing dots are still pointing to files and thus redirected to the server. For example, if you have an url such as /search/firsname.lastname you would need to add a handler for this.